[U-Boot] [PATCH v4 1/5] dma: lpc32xx: add DMA driver

[LEMIEUX, SYLVAIN]

Hi Marek,

See comment and question below.

> -----Original Message-----
> From: Marek Vasut [mailto:marex at denx.de]
> Sent: 4-Aug-15 5:32 PM
>
> On Tuesday, August 04, 2015 at 11:04:38 PM, slemieux.tyco at gmail.com wrote:
> > From: Sylvain Lemieux <slemieux at tycoint.com>
> >
> > Incorporate DMA driver from legacy LPCLinux NXP BSP.
> > The files taken from the legacy patch are:
> > - lpc32xx DMA driver
> > - lpc3250 header file DMA registers definition.
> >
> > The legacy driver was updated and clean-up as part of the integration with
> > the latest u-boot.
> >
> > Signed-off-by: Sylvain Lemieux <slemieux at tycoint.com>
>
> [...]
>
> > +
> > +/*
> > + * The "dmac_ll" structure is mapping the DMA channel register,
> > + * as per UM10326, "LPC32x0 and LPC32x0/01 User manual" - Rev. 3
> > + * tables 84, 85, 86 & 87.
> > + *
> > + * The DMA client (ex. NAND SLC) can use this macro to write the
> > + * next DMA linked list item address.
> > + */
> > +#define lpc32xx_dmac_next_lli(x) (uint32_t)x
>
> Ew, and it's not even used :-)

This is used inside "drivers/mtd/nand/lpc32xx_nand_slc.c";
Refer to this patch for details: https://patchwork.ozlabs.org/patch/503815/

Are we OK to keep this define there?

>
> > +/* DMA linked list structure used with a channel's LLI register */
> > +struct lpc32xx_dmac_ll {
> > +   u32 dma_src;
> > +   u32 dma_dest;
> > +   u32 next_lli;
> > +   u32 next_ctrl;
> > +};
>
> [...]
>
> > +int lpc32xx_dma_wait_status(int channel)
> > +{
> > +   unsigned long start;
> > +
> > +   start = get_timer(0);
> > +   while (1) {
>
> Here , you can do
>
> reg = readl();
> reg |= readl();
> if (reg & BIT_MASK())
>     break;
>
Will update the patch.

> > +           if (((readl(&dma->raw_tc_stat) | readl(dma->raw_err_stat))
> > +                & BIT_MASK(channel)) != 0)
> > +                   break;
> > +
> > +           if (get_timer(start) > 10000)
> > +                   return -1;
> > +
> > +           udelay(1);
> > +   }
> > +
> > +   if (unlikely(readl(&dma->raw_err_stat) & BIT_MASK(channel))) {
> > +           setbits_le32(&dma->int_err_clear, BIT_MASK(channel));
> > +           setbits_le32(&dma->raw_err_stat, BIT_MASK(channel));
> > +           return -1;
> > +   }
> > +   setbits_le32(&dma->int_tc_clear, BIT_MASK(channel));
> > +   setbits_le32(&dma->raw_tc_stat, BIT_MASK(channel));
> > +   return 0;
> > +}
>
> Other than that,
>
> Acked-by: Marek Vasut <marex at denx.de>

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